Named properties allow arbitrary data to be attached to objects within
the toolkit. For example:
ok = dt_setinteger(ob, 6, "myprop", 11);
printf("Value is %d.\n", dt_integer(ob, 6, "myprop"));
Value is 11.
Named properties are strongly typed. That is, you must specify
exactly the type of property when you set and get it. There is never
any anbiguity.
Values are boolean, handle, integer, real, string.
Named properties are unlimited. Any number of named properties may be
attached to an object, provided they have different names.
Like an adjunct, once a named property is set for an object, it stays
attached to the object until the object is deallocated (or the property
is changed).
